I want to turn now to London, where there were some tense moments this morning. A car crashed into a traffic barrier outside Parliament. At least two people were injured, though these injuries do fortunately appear not to be serious. Police arrested the driver of this vehicle, and Scotland Yard says they are treating this crash as a terror attack. President Trump has tweeted this morning about this incident, saying, quote, “another terrorist attack in London. These animals are crazy and must be dealt with through toughness and strength,” end quote - that tweet from President Trump this morning. Joining us now is NPR’s Frank Langfitt in London. Hi, Frank.

FRANK LANGFITT, BYLINE: Hey. Good morning, David.

GREENE: So tell us exactly what happened here based on what you know so far.

LANGFITT: Sure. So it's around 7:30 in the morning. There's a silver Ford Fiesta driving past Big Ben at a normal speed - nothing suspicious at all. Suddenly, it swerves, goes across a median, hits a couple of cyclists and then appears to try to mow down three police officers who leap out of the way. And then the car slams into a barrier. Other police reinforcements arrive. The police pull the man from the car and handcuff him.

GREENE: OK. I mean, it sounds like this could have been worse than it was.

LANGFITT: Much. You know, a lot worse, David. Absolutely.

GREENE: OK. So they arrested the driver. What do we know about the driver right now?

LANGFITT: Very little. He's in his late 20s. He's black. But they have not identified him or given any specific motive. At the moment, the police are saying they don't think he was known to the cops or to MI5, the domestic security here. There's no other suspect. And at the moment, they think there's no other risk to London. Of course, one person who was injured actually has been discharged, so that's good news. And one is still in the hospital.

GREENE: So Frank, some of the significance of this story is the location. It's not just, I mean, a notable location near Parliament, but a place that, sadly, has seen terrorism before.

LANGFITT: Yeah. This is becoming pretty common, actually. This is the second terror attack around Parliament in under 18 months. And there was a third attempted attack on the area, as well. This is the seat of British power. It's a symbolic target. If you want to go back - you know, you and I discussed this on the air back in March of last year. There was an Islamist radical who drove across Westminster Bridge. He killed four pedestrians then got inside the gates of Parliament and stabbed to death a police officer before, the attacker, he was shot and killed. The next month - this didn't get much publicity, but, very interesting - police arrested an al-Qaida bomb-maker who had three knives in Parliament Square. He was planning to go and try to stab members of Parliament. And, in addition to that, in the city, we've had three other terror attacks that have cost lives.

GREENE: Well, given that history, people who are in this area this morning, were they thinking, you know, my God, here we go again?

LANGFITT: It was really interesting. I got the news of this when I was on the train on the way in. And people seemed to take it in stride. I looked at all the faces of people. Some people were reading their books. Some were reading on their phones. And there wasn't a big reaction. One woman I was sitting across from said, again? Another said, you know, she had called to make sure her husband was safe, but this had not affected her. It was very interesting.

When I went up to Westminster Bridge, which goes across the Thames towards Parliament, there were government workers trying to get to work. And, frankly - and I don't want this to make them sound callous, but, they seemed more focused on how to get around the police cordons to get to work than anything else. And I think that speaks to the frequency with which we've seen this in the last, you know, year and a half. That said, I did speak with one new mother who said that she's been avoiding the Tube as much as possible because she's, you know, afraid at some point there'll be a successful Tube bombing.

GREENE: Are these kinds of attacks changing Europe, Frank?

LANGFITT: Well, what's really interesting, David, is that the modus operandi has really changed. If you go back, there used to be bombings - and, we have had bombings here in the last 18 months. We had one big one up in Manchester. But what you're seeing is people using vehicles to attack people on the roads. And this happened, of course, in Barcelona. This also happened in Nice. And it's happened, I believe, now it would be three times here in London alone. And this is a very easy, easy crime of opportunity. It's very, very hard to defend against. And a lot of analysts that I've been talking to over the last 18 months say we expect to see more of this. Recently, you know, we've had a lull for a long time without an attack here in London. But, frankly, I was kind of waiting - and probably a lot of people were waiting - to see, when would there be another car attack?

GREENE: OK. Again, that car swerving this morning, injuring some. They don't appear serious, although the police are treating it as a terror attack at this point. NPR's Frank Langfitt reporting from London. Thank you, Frank.